An offensively large dump. A crap of such grave proportions, that should the cruel bastard decide to deliver it whole (without any effort of pinching it off, flushing in between), such a deed would amount to nothing less than an act of pure, unabated vandalism; a destruction of public or private property, with due compensation and mandatory letter of apology to the caretaker of said toilet.

Accomplice: Where ya goin?
Offender: Just poppin' into the loo to squeeze out a fat rat.
*closes door*
*speaking through the door, the conversation continues*
Accomplice: Have you prepared you're letter of apology?
Offender: Aye, writing it on the walls as we speak.

"The fuck?! Who broke my toilet? Whoever just laid this brick, fess up now, or when I find out, I swear I'll shove this fat rat back up your cursed cornhole so far, you'll be belching farts for the next week and a half!"